It is well known to design air channeling structures in frontal regions of automobiles and direct air into one or more engine intakes, radiators, and/or around the engine.
Although desirable characteristics for air flows to engine intakes and those for radiators share many common attributes such as high flow rates, and maintaining low temperatures; air flows for engine intakes have several additional desirable characteristics. First, such air flows should be free or substantially free, of entrained particles of dirt, dust, water, snow, ice, and the like. Although air directed to an engine intake subsequently passes through one or more filter elements, it is preferred that such air streams be free of entrained particles which would otherwise be collected at the filter elements and thus block or interfere with air flow at that location. It is also desirable that the amount of air directed to an engine intake be relatively high, or at least in excess of demands from the engine.
It is known in the fields of material handling and particularly, in gas-solid separations, that entrained particles can be separated from a moving air flow by causing sudden changes in the direction of the air flow. Due to differences in mass and thus inertia between such particles relative to air, entrained particles can be diverted away from a redirected air flow. Cyclones and labyrinth separators are based upon this phenomenon.
Vehicle designers have incorporated a range of structures for directing air flows from the front and/or underside of a vehicle to an engine intake. For example, US Patent Publication 2005/0230162 describes a front structure for a vehicle that collects and directs air through a tortuous flow path to attempt to rid the air flow from entrained snow or rain.
A significant advance was described in a collection of patents and published patent applications to the same assignee as the present application, namely U.S. Pat. Nos. 7,234,555; 7,237,635; and 2006/0006011 for example. In FIG. 8 of each of these documents, an S-shaped air flow is described in which air is collected behind a grill and then reversed in direction as it passes through a screen provided in a bulkhead cover. After passing through such cover, the air flow is then reversed in direction and sent to an engine intake.
Although the air intake system described in the noted patent documents of the assignee provide numerous benefits, ever-changing vehicle designs and increasingly demanding requirements create a need for yet further improvements.